[RFC PATCH 07/15] pwm: move the enabled/disabled info to pwm_state struct

Boris Brezillon
2015-07-01T08:21:53Z

Prepare the transition to PWM atomic update by moving the enabled/disabled
state into the pwm_state struct. This way we can easily update the whole
PWM state by copying the new state in the ->state field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/pwm/core.c | 15 ++++++++++++---
include/linux/pwm.h | 6 +++---
2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index a6bc8e6..3e830ce 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -474,8 +474,15 @@ EXPORT_SYMBOL_GPL(pwm_set_polarity);
*/
int pwm_enable(struct pwm_device *pwm)
{
- if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
- return pwm->chip->ops->enable(pwm->chip, pwm);
+ if (pwm && !pwm_is_enabled(pwm)) {
+ int err;
+
+ err = pwm->chip->ops->enable(pwm->chip, pwm);
+ if (!err)
+ pwm->state.enabled = true;
+
+ return err;
+ }

return pwm ? 0 : -EINVAL;
}
@@ -487,8 +494,10 @@ EXPORT_SYMBOL_GPL(pwm_enable);
*/
void pwm_disable(struct pwm_device *pwm)
{
- if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm && pwm_is_enabled(pwm)) {
pwm->chip->ops->disable(pwm->chip, pwm);
+ pwm->state.enabled = false;
+ }
}
EXPORT_SYMBOL_GPL(pwm_disable);

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index bed7234..fd3e0f0 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -75,14 +75,14 @@ enum pwm_polarity {

enum {
PWMF_REQUESTED = 1 << 0,
- PWMF_ENABLED = 1 << 1,
- PWMF_EXPORTED = 1 << 2,
+ PWMF_EXPORTED = 1 << 1,
};

struct pwm_state {
unsigned int period; /* in nanoseconds */
unsigned int duty_cycle; /* in nanoseconds */
enum pwm_polarity polarity;
+ bool enabled;
};

struct pwm_device {
@@ -98,7 +98,7 @@ struct pwm_device {

static inline bool pwm_is_enabled(const struct pwm_device *pwm)
{
- return test_bit(PWMF_ENABLED, &pwm->flags);
+ return pwm->state.enabled;
}

static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
--
1.9.1